Processing of substrates in semiconductor electronic device manufacturing is generally carried out in multiple process tools, where substrates travel between process tools in substrate carriers. Substrate carriers may be sealable containers carrying from one to, e.g., 25 substrates, and may be, e.g., Front Opening Unified Pods or FOUPs. A substrate carrier may be docked to a load port, which may be mounted to a factory interface, such as, e.g., an Equipment Front End Module or EFEM. The factory interface may be coupled to a process tool and may include a robot substrate handler operable to transfer substrates between a substrate carrier and the process tool.
An environmentally-controlled atmosphere may be provided within and between the substrate carrier, the factory interface, and the process tool. That is, because exposure to, e.g., air (particularly oxygen, a reactive gas) and moisture may adversely affect substrate properties and substrate processing due to oxidation, substrates may be kept in a non-reactive gas environment. A non-reactive gas may be, e.g., nitrogen. Any leakage in that environment occurring during, e.g., a transfer of substrates from a substrate carrier to a factory interface via a load port may accordingly contaminate substrates being processed and/or adversely affect processes being performed on the substrates. This may result in the manufacture of defective electronic devices on those substrates. Existing electronic device manufacturing systems may therefore benefit from improved load port operation that reduces or eliminates such leakage.